Fan blade structure



Feb. 12, 1952 G. MOELLER FAN BLADE STRUCTURE Filed April 10, 1945 IINVENTOR. 61 60 541 Aha/lei:

Patented Feb. 12, 1952 UNITED STATES OFFICE 2,585,255 BLADE STRUCTUREGeorge L. Mueller, St. Louis, Mo., assig nor, by inesne assignments, ie"Knapp-Monarch St. Lbuis, M0., -"a' corporation of Delaware ApplicationApril :10, 1945, Serial No. 537,571

2 Claims. (Cl. 170 -1595) 1 My present invention relates to a fan bladestrilctureof simple and light construction.

One object of the invention is to providea fan blade structure formed of'a non-metallic material such as paper base material, or laminated harmto anyone happening to come in contact blade Ill.

with the blade while it is rotating.

Still another object is to provide a fan blade which can be cut from asheet of thermo-plastic material and then heated and formed to thedesired shape to produce pitch for air delivery, or

cut from a semi-cured material which becomes completely cured and takesa set upon the application thereto of pressure and/ or heat.

With these and other objects in view, my invention consists in theconstruction and arrangement and combination of the various partsthereof whereby the objects contemplated are attained as hereinaftermore fully set forth, pointed out in my claims and illustrated in theaccompanying drawings, in which:

Figure 1 is a side elevation of a fan blade structure embodyfiig myinvention;

Figure 2 is a front elevation thereof showing in dotted lines theoriginal fiat shape of the fan blades;

Figure 3 is a rear view of the structure;

Figure 4 is an enlarged sectional view on the line 44 of Figure 1; and

Figure 5 is a bottom plan view of the hub and center plate of Figure 4before the fan blades are connected thereto.

0n the accompanying drawings I have used the reference numeral H] toindicate a fan blade. Four of the blades are shown and they areconnected together at the center by a disk-like portion l2, the fourblades l0 and the portion [2 being all formed of a single sheet ofmaterial and in the initially fiat shape shown by dotted lines Illa inFigures 1 and 2.

The disk-like portion I2 is reinforced by a metal plate M of disk-likecharacter formed on a hub [6. The hub 16 is adapted to be secured to ashaft l8 of an electric motor or the like as by a set screw 20. Theplate M has a central extension 22 formed with a pair of beads 24 whichfit a similarly shaped center hole 26 of the disk-like portion 12 of thetem blades. The disk like 'portion is also provided with perforations 28through which studs 30 of the plate 14 extend, and for assembly purposesthese are riveted as at '32 over a metal disk 3 The central portion I 2hf the tan blades is thereby confined between th'e disks l4 and 3 1which suitably reinforce the blades and provide a :good mechanicalconnection to a shaft for rotating the fan structure.

I lit will be noted thatadjacent the peripheryof the disk Itcorrugations are formed the material of the fan blades ID for thepurpose of reinforcing the blades at the transition point from the hubplate I 4 to the main body of each The method involved in forming thefan structure is as follows: First, the blades l0 and the center diskportion l2 are cut from a single sheet of non-metallic material such asa thermo-plastic or a laminated phenolic plastic to the shape shown bydotted lines in Figures 1 and 2. The blades are then heated in order tomake them plastic and while heated they are formed in a press to theproper angle or pitch for air delivery upon rotation, these angles beingbest shown in Figure 2. The blade structure is then permitted to cool sothat the blades set in the shape to which they were formed in the pressand retain such shape under ordinary moisture and temperatureconditions.

In the case of a blade which is made of semicured material the bladebecomes completely cured and takes its set when it is finally formed inthe press, the curing resulting from the pressure produced by the press.At the same time, heat may be applied in addition to the pressure tocompletely cure the material.

After the blades are formed as just described they are assembledrelative to the hub 16 in the manner already described to form acompleted fan blade structure which can be mounted on a shaft of a fanmotor or the like.

The resulting structure is light in weight and thus safer to operate. Itis inexpensive to manufacture both from the material and laborstandpoint. The material is readily cut in a die and formed in a pressafter the material is heated to make it plastic. The subsequentoperations of assembling the hub and the disk 34 are simple to perform,and balancing the structure may be quickly and conveniently done bytrimming off the heavy blades until proper balance is secured.

Some changes may be made in the construction and arrangement of theparts of my fan structure and the steps of the method can be variedwithout departing from the real spirit and purpose of my invention, andit is my intention to cover by my claims any modified forms of structureor use of mechanical equivalents which may be reasonably included withintheir scope without sacrificing any of the advantages thereof.

I claim as my invention:

1. In a fan blade structure, a plurality of blades integral with acentral disc portion, said blades and disc portion being of non-metallicmaterial, said blades being shaped to provide pitch for air deliveryresulting from rotation of the structure, and a metallic hub for saidfan blades having a plate-like portion, said central disc portion ofsaid fan blade structure being connected to said plate-like portion,each blade at its innermost portion adjacent said disc portion beingarcuate shaped in radial cross-section, and said inner-most portionhaving reinforcin corrugations extending radially outward from theperiphery of said central disc portion.

2. A fan blade structure comprising a sheet of non-metallic materialshaped to provide a plurality of blades connected together by a cuppedcentral disk-like portion, a metallic reinforcing disk therefor, saidblades being permanently formed to produce pitch for air deliveryresulting from rotation of the structure, and a metallic hub for saidstructure having a plate-like portion provided with studs extendingthrough said disk-like portion and said reinforcing disk and 5 to themain portion of the blade, said corrugations being entirely opposite thecupped side of the plane of said plate-like portion of said hub. GEORGEL. MOELLER.

1 REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,773,349 Bothezat Aug. 19, 19302,016,568 Zinser Oct. 8, 1935 2,033,345 Lee Mar. 10, 1936 2,095,162 WoodOct. 5, 1937 2,100,891 Zinser Nov. 30, 1937 2,202,042 Blount May 28,1940 2,234,319 Preston Mar. 11, 1941 2,251,887 Larsh Aug. 5, 19412,251,888 Leflar Aug. 5, 1941 2,346,552 Brotz Apr. 11, 1944 2,370,652Frisbie Mar. 6, 1945 2,378,049 Upson June 12, 1945 FOREIGN PATENTSNumber Country Date 212,488 Great Britain Mar. 13, 1924

